INTRODUCTION
The Zgrass TRANS PACKAGE, generally referred to as TRANS for short, is a
set of macros and swap modules designed for modeling three-dimensional vector
(wire-frame) objects on the Datamax UV-1 Zgrass Graphics System. It is targeted
for people who are familiar with the basic programming concepts of the Zgrass
language, as well as three-dimensional coordinates, and geometric
transformations.
The basic approach to TRANS involves three steps:
- Object Creation: objects are defined by storing the values of X, Y, Z, and
COLORMODE in 2-dimensional arrays. The macro GETOBJ offers a menu of macros
which can be used to define wire-frame objects.
- Transformation Definition: geometric transformations are defined through the
use of commands such as HOME, MOVE, ROT, SCALE3D, and SHEAR. Successive
operations are multiplied together and saved in a transformation array.
- Image Display: images are displayed by (optionally) applying the
transformation array to the coordinates as the vectors are drawn on the screen
with the commands TDISP and ODISP. Simple perspective can be used to clarify
the three-dimensional nature of the images with the PDISP command.
Screen animations are easily created with incremental transformations
displayed on different screens. These are played back by 'flipping' through the
screens in sequence with the FLIP command. The DEMO macros illustrate this
technique.
The TRANS Package consists of:
1) Getting Started with TRANS
2) Introduction
3) Using the TRANS Package
4) Programming Notes:
Array Types and Data Structures
Space Considerations
The Coordinate System
Creating Objects
5) Summary of TRANS Commands
6) ZGRASS TRANS Package Glossary